AM laser radar (ladar) technology is known in the art. An existing 3D chirped AM laser radar architecture is modified with high-bandwidth optical FM sensing. A practical implementation of the scheme, which is based on parametric down conversion, is described below. Such an improved architecture improves the special resolution of the laser radar from ˜30 cm down to ˜1 mm.
3D ladars have been proven efficient in detecting threats through partial covers, e.g., leave coverage. See B. L. Stann, W. C. Ruff, and Z. G. Sztankay, “High range resolution ladar”, U.S. Pat. No. 5,608,514, 1997; B. L. Stann, W. C. Ruff, and Z. G. Sztankay, “Scannerless ladar architecture employing focal plane detector arrays and FM-cw ranging theory”, U.S. Pat. No. 5,877,851 and, Greg Sztankay, “Chirped-AM 3D imaging laser radar for DOD applications”, invited talk, PtuF3, CLEO/PhAST, San Francisco, 2004, the disclosures of which are hereby incorporated herein by reference.
Applications of this technology include ground and airborne reconnaissance, target acquisition/identification, and robotic vehicle navigation. The spatial resolution of such laser radars is of great importance, since it determines the reliability of target/obstacle identification. A hybrid chirped AM/FM laser radar scheme is disclosed herein that offers vastly improved spatial resolution over the current state of the art represented by the documents cited above, for example.